This directory contains source code for Bitcart core part: daemons.

All daemons inherit from others, building a dependency graph.

All daemons must inherit from base.py.

BaseDaemon has the following properties:

• Daemon is an aiohttp web application

• Daemon supports "spec" (see spec directory) to provide better exception messages to clients

• Daemon can load different environment variables, under it's name prefix COIN_ENVNAME

• Daemon supports websocket notifications

• Daemon is a server following an extended variant of JSON-RPC 2.0 specification, it allows passing both positional and named parameters for example, passing {"id": 0, "method": "method", "params": ["x", "y", {"xpub": "xpub..."}]} is equivalent to calling method("x", "y", xpub="xpub...")

• Daemon exposes 3 endpoints

  • POST / - main execution endpoint, used for calling different methods provided. Override execute_method in your subclass to support it
  • GET /ws - websocket endpoint, used to listen for events. Where needed, call notify_websockets in your subclass to trigger notification on all websockets
  • GET /spec - returns daemon specification, for more details see daemon spec directory

Unless your coin is completely custom, usually there is no need to implement everything from scratch.

Most coins are based on bitcoin directly or not, and may have electrum wallet existing.

Note: to specify which electrum module to use, and if you need to customize something by using it's properties, don't do this:

import customelectrum

class MyDaemon(BTCDaemon):
  electrum = customdaemon
  NETWORK_MAPPING = {"mainnet": electrum.networks.set_mainnet}

It would make all daemons dependent on your coin's daemon also require your customelectrum module to be installed. Instead do:

class MyDaemon(BTCDaemon):
  def load_electrum(self):
    import customelectrum

    self.electrum = customelectrum
    self.NETWORK_MAPPING = {"mainnet": self.electrum.networks.set_mainnet}

It would import the customelectrum module only on startup

BTCDaemon is an implementation of Bitcart daemon using electrum wallet for it's operations. Read btc.py source code to check what you need to override in your subclass.

class CustomDaemon(BTCDaemon):
    name = "COIN"
    DEFAULT_PORT = 5000 # assigned in order of addition
    electrum = custom_electrum

In most cases that's how approximate implementation of electrum-based daemons might look like.

If your coin is based on BCH and has a fork of electron cash instead, you should inherit from BCH daemon, as electron cash is too different from original electrum.